This invention relates to closures for dunnage bags such as are used between pallets to cushion cargo in transit and particularly to a valve that features secure a flexible cap that readily deforms to permit sealing the bag.
Common practice to protect cargo stacked on pallets during transit is to position bags filled with moderately compressed air between the rows of pallets. The bags are typically vinyl or reinforced paper.
Because of the large number of bags in use there has been much interest in reducing the cost of the bags and associated equipment and reducing the time and inconvenience required to place and inflate the bags and then deflate and remove of the bag after transit is complete. A number of disclosures have appeared to reduce these costs and inconveniences.
For example, U.S. Pat. No. 4,073,389 to Angarola et al discloses a housing engaging a spring loaded plug that permits one way entry of air into the bag. The valve tends to disfunction with aging of the spring.
U.S. Pat. No. 4,102,364 to Leslie et al discloses a system for rapid pressurizing the air inside the bag from a source of high pressure air.
U.S. Pat. Nos. 4,146,069 and 4,146,070 to Angarola et al discloses another system for rapid filling using a stream of pressurized air to aspirate ambient air into the bag.
The foregoing systems require a source of high compressed air which are not always available.
U.S. Pat. No. 5,111,838 to Langston discloses a spring loaded valve member movable to open a passage and threaded opening to engage an air hose.
U.S Pat. No. 5,806,572 discloses an apparatus for inflating a bag to a desired limit.
U.S. Pat. No. 6,053,222 discloses a gun that both inflates the bag when required and accelerates deflation of the bag when required.
It is an object of this invention to provide a valve for a container such as a dunnage bag which has several advantages over the valves of the prior art.
One advantage is that the outmost surface of the valve is substantially coincident with the surface of the bag. This is an important feature for preventing damage to the bag or release of air due to inadvertent contact of the valve with neighboring objects such as another pallet.
Another advantage is avoidance of leakage of air from the bag such as often occurs with threaded valves of the prior art that are not completely tightened.
Another advantage of the device is that it can be injected molded as two integrally formed parts thereby substantially minimizing the cost to produce the valve.
Another advantage is that the valve of this invention does not rely on spring biasing that is prone to degrade with time.
This invention is directed toward an inner bowl having a flange that is laminated to the inside surface around a hole of the bag and a flexible outer bowl having a flange that is laminated to the outside surface around an opening in the bag. When inflating the bag, air enters through a tube in the outer bowl and passes through apertures in the inner bowl and into the bag. After the bag is fully inflated, the outer bowl is pressed against the inner bowl so as to close off the apertures to prevent the gas from escaping. The gas is further sealed by a cap that engages the entry end of the outside bowl.